Advances in Catalysts for Electrochemical Nitrate Reduction: An Overview of a Sustainable Approach to Mitigating Pollution

This study describes the development of catalysts for the electrochemical reduction of nitrate to ammonia, a promising approach for the integration of renewable energy sources and an alternative for ammonia production in agriculture. Nevertheless, nitrate pollution, mainly caused by industrial effluents, wastewater and agricultural runoff, poses a serious environmental and health risk, including eutrophication and groundwater contamination. Electrochemical nitrate reduction (ENR) has proven to be a viable strategy to reduce nitrate pollution by selectively converting nitrates into environmentally friendly products such as nitrogen gas or value-added compounds. Therefore, this study critically analyzes recent advances in ENR catalysts, focusing on metal-organic frameworks (MOFs), bimetallic and alloy systems, carbon-based electrocatalysts, and noble and non-noble metal catalysts. Particular attention is paid to insights into the mechanism, selectivity, stability and efficiency as well as scalability for practical applications. In addition, challenges such as catalyst deactivation, ammonia selectivity and energy efficiency should be investigated to identify strategies to improve performance. Catalytic efficiency is influenced by several factors, including reaction conditions, catalyst structure, loading methods and electrode interfaces. The catalytic activity, selectivity, Faradaic efficiency, current density and durability of different catalysts are compared by examining the structural, compositional and electrochemical properties that determine performance, providing valuable insights for future advances in the field. Ultimately, this study reveals innovative approaches for catalyst development and mechanism understanding, paving the way for a new era of sustainable and cost-effective ammonia production.